Why do I take issue with those who argue that, in refusing to turn a blind eye to "minor" infringements, the authorities are simply being petty and heavyhanded? Quite simply, because refusing to accept any form of anti-social behaviour is the cornerstone of zero tolerance - a term that is much talked about, often suggested as a way of curbing our wave of lawlessness, but widely misunderstood. Having witnessed the effects of zero tolerance at first hand, I know that it works - but only if you treat all minor infringements with due seriousness and don't just pick on easy targets while ignoring the more hardened thugs.

My experiences date back to the late-Eighties, when my family and I lived for two years in frenetic New York. When we arrived, with three children under the age of ten, the city was so dangerous that there were times that we felt like prisoners in our 18th floor apartment on the Upper East Side. Supposedly one of the more affluent neighbourhoods, the nearby playground was a haven for crack-smokers. Drunken pan-handlers made walking to the shops down Third Avenue a daily ordeal. Kathleen Jennings wearing flip-flops Menacing squeegee merchants besieged our car at traffic lights.

One Sunday, playing baseball in Central Park, we were set upon by teenagers who stole the bat and threatened to attack us with it. A few days later, in that same spot, a jogger was gang-raped and beaten almost to death by more than a dozen masked youths who sprang, whooping, from the trees. This rampant lawlessness and the insidious fear it instilled was as constant as the wailing police sirens, tarnishing an otherwise enjoyable stay.

By the mid-Nineties, however, when I returned to visit, the city was barely recognisable. The aggressive beggars and street gangs had vanished, as had the sickly fug of crack pipe smoke.

Yesiree! We need to rid the streets of 12 year old cocktail-sausage throwers (cocktail-sausages, mind!), Cub Scout leaders who put their feet on train seats and girls who get their tits out on a Friday night. That'll make the streets of south London safe!